Particle Model of Light Worksheet 7: Refraction - Diagrams showing light ray paths as they pass from air to water and from water to air.

Problem Analysis:

The worksheet involves understanding the concept of refraction, which is the bending of light as it passes from one medium to another (e.g., from air to water or vice versa). The key principles to apply here are:

1. Snell's Law: Describes how light bends when passing between two media with different refractive indices.
\[
n_1 \sin \theta_1 = n_2 \sin \theta_2
\]
where \( n_1 \) and \( n_2 \) are the refractive indices of the two media, and \( \theta_1 \) and \( \theta_2 \) are the angles of incidence and refraction, respectively.

2. Refractive Index: Water has a higher refractive index than air (\( n_{\text{water}} > n_{\text{air}} \)), so light bends toward the normal when entering water and away from the normal when exiting water.

Solution to Each Part:

#### Part 1: Light Passing from Air into Water
- Given: Light rays travel from air into water.
- Key Concept: When light travels from a less dense medium (air) to a more dense medium (water), it bends toward the normal.
- Steps:
1. Draw the boundary between air and water as a horizontal line.
2. Draw the incident rays in the air, starting from the light source above the boundary.
3. At the boundary, draw the normal (a perpendicular line to the boundary).
4. Use Snell's Law to determine the angle of refraction. Since the refractive index of water is greater than that of air, the refracted rays will bend toward the normal.
5. Extend the refracted rays into the water.
6. Indicate the observer's eyes in the water, positioned such that they can see each refracted ray.

- Diagram:
- Incident rays in air bend toward the normal upon entering water.
- Refracted rays continue straight in water.
- Observer's eyes are placed in the water, aligned with the refracted rays.

#### Part 2: Light Passing from Water into Air
- Given: Light rays travel from water into air.
- Key Concept: When light travels from a more dense medium (water) to a less dense medium (air), it bends away from the normal.
- Steps:
1. Draw the boundary between water and air as a horizontal line.
2. Draw the incident rays in the water, starting from the light source below the boundary.
3. At the boundary, draw the normal (a perpendicular line to the boundary).
4. Use Snell's Law to determine the angle of refraction. Since the refractive index of air is less than that of water, the refracted rays will bend away from the normal.
5. Extend the refracted rays into the air.
6. Indicate the observer's eyes in the air, positioned such that they can see each refracted ray.

- Diagram:
- Incident rays in water bend away from the normal upon entering air.
- Refracted rays continue straight in air.
- Observer's eyes are placed in the air, aligned with the refracted rays.

Final Answer:

The solutions involve drawing diagrams for both parts, showing the path of light rays as they refract at the boundary between air and water. Here is a summary of the steps for each part:

#### Part 1: Light from Air to Water
1. Draw incident rays in air.
2. At the boundary, bend the rays toward the normal.
3. Extend the refracted rays into water.
4. Place observer's eyes in water, aligned with the refracted rays.

#### Part 2: Light from Water to Air
1. Draw incident rays in water.
2. At the boundary, bend the rays away from the normal.
3. Extend the refracted rays into air.
4. Place observer's eyes in air, aligned with the refracted rays.

The final answer is encapsulated in the diagrams, but since I cannot draw them here, the explanation provides the necessary steps to construct the diagrams accurately.

\boxed{\text{Follow the steps outlined above to complete the diagrams.}}